The present invention relates to a golf club head in which a resin member made of a fiber reinforced resin is employed at least in a part of a crown portion.
In recent years, for example, as described in Japanese Published patent application 2003-111874, there has been proposed a so-called compound type golf club head formed by firmly fixing a resin member structuring a part of a crown portion and made of a fiber reinforced resin, and a head main body made of a metal material.
The composite type golf club head as mentioned above can reduce its weight by using a fiber reinforced resin having a small specific gravity. Accordingly, for example, it is possible to enlarge a head volume. Further, the reduced weight can be more distributed in a side portion of a head, for example, a toe or a heel, a back face and the like. These can increase a moment of inertia around a gravity point of the head and increase a depth of center of gravity point. Further, if the fiber reinforce resin is used in the crown portion, it is possible to reduce a weight of an upper portion side of the head, so that it serves for achieving a low gravity point. As mentioned above, in the composite head, it is possible to increase a freedom of designing the weight distribution.
However, in the composite type golf club mentioned above, breakage of the resin member tends to be generated due to an impact at the time of hitting a ball. In order to prevent the resin member from being broken, there can be considered to make a thickness of the resin member large, however, in accordance with this method, it is impossible to obtain a substantial weight reducing effect by the resin member. As mentioned above, in the composite type head, there is a room for further improving durability. Accordingly, in the composite type head, it can be said that an improvement is necessary while paying attention to an angle of orientation of the fiber in the resin member and a strength or an elastic modulus included in a matrix resin.